Here we speculate on the molecular pathways that may couple the circadian machinery to breast cancer.

Melatonin,at physiological concentration,suppresses estrogen receptor(ER) gene, modulates several estrogen dependent regulatory proteins and pro-oncogenes, inhibits cell proliferation, and impairs the metastatic capacity of MCF-7 human breast cancer cells.

Sleep disordered breathing (SDB)are associated with menopause. Fibromyalgia patients have increased central nervous system levels of the nociceptive neuropeptide substance P (SP). High SP and low serotonin have significant potential to affect sleep and mood.

Baseline salivary cortisol and melatonin were not significantly correlated with STAI scores and did not change significantly following reflexology.These findings will be transferred to a study involving breast cancer patients where effects display disregulation of cortisol and melatonin secretion.

In ovariectomized rats,melatonin reduced food intake and partially prevented the increase of body weight and cholesterol, without changing leptin levels.

Nurses who attend night shifts should undergo strict and periodical breast cancer screening, since the risk is significantly increased in this population.

Identification of CBM as a specific inhibitor of AKR1C3 and the resultant effects on prostate and breast cancer cells.

No evidence was found for an association between shift work and breast or prostate cancer, or all cancer sites combined among shift workers.

In premenopausal women, the urinary aMT6-s level was significantly positively associated with percent mammographic density. No evidence that the melatonin level is inversely associated with mammographic density.

Indole-3-carbinol (I3C)induces a G1 cell cycle arrest of human breast cancer cells,whereas both tryptophol and melatonin failed to induce the cell cycle arrest.